1. Field of the Invention
The present invention generally relates to closure devices. More specifically, the invention relates to a closure device for closing physical apertures, such as vascular or septal apertures.
2. Description of Related Art
The heart is generally comprised of four chambers: the left and right atrium and left and right ventricle. Separating the left and right sides of the heart are two walls, or septa. The wall between the two atria is the interatrial septum, and the wall between the two ventricles is the interventricular septum. There are several defects which can affect the septa of both children and adults, including patent ductus arteriosus, patent foramen ovale (PFO), arterial septal defects (ASDs), and ventricular septal defects (VSDs). Although the causes and physical characteristics of these defects vary by type, each of these defects is generally an aperture, flap, or hole in the septum which allows blood to shunt between chambers in the heart where there is no blood flow in a normal, healthy heart. This abnormal shunt can cause a variety of problems.
Normally, permanently repairing certain cardiac defects in adults and children requires open heart surgery, which is a risky, painful, and expensive procedure. Surgery for closure of a heart defect is major heart surgery, which requires the patient to undergo general anesthesia and opening of the chest cavity. The patient must spend several days in the hospital and takes several weeks to be able to return to normal levels of activity.
To avoid the risks and discomfort associated with open heart surgery, modern occlusion or closure devices have been developed that are small, implantable, and capable of being delivered to the heart through a catheter. Rather than surgery, a catheter inserted into a major blood vessel allows an occlusion device to be deployed by moving the device through the catheter to the treatment site within the body. This procedure is performed in a cardiac cathlab and avoids the risks, pain, and long recovery associated with open heart surgery.
There are currently several types of closure devices capable of being inserted via a catheter including button devices, collapsible umbrella-like structures, and plug-like devices. These modem closure devices can repair a wide range of cardiac defects, including patent foramen ovale, patent ductus arteriosus, atrial septal defects, ventricular septal defects, and may occlude other cardiac and non-cardiac apertures. Many of the conventional closure devices can be technically complex, bulky and difficult to deploy in a precise location. In addition, such devices may be difficult or impossible to retrieve and/or reposition should initial positioning not be satisfactory.